Nope. Try again.
See http://911research.wtc7.net/cache/wtc/analysis/wtc7/nty_burningdiesel.html for a clue.
BTW it was Salomon Brothers in WTC 7.
I work in a building with three huge steam boilers (diesel fired) and a backup generator in the basement. I don't know if the generator is diesel fired as well, but I know the boilers are because my husband's company put in a bid for maintaining them.
If we ever have a fire it's going to be a mess with all that fuel stored down there. But this is a five-story, old fashioned heavy steel-and-concrete building, not a large office tower.
Most buildings that depend on elevators are required to have backup generators.
I’n not saying that that was the cause of any failure, since neither diesel, nor jet fuel burn at a high enough temperature to affect the hardness of steel, unless a large draft of oxygen is present to increase the rate of combustion. - These are high energy fuels to be sure, but they are slow burners at normal conditions.